OBS ER 
OBSERVA'TOR,./! [obfervateur, Fr. from obfervo, Lat.] 
One that obferves; a remarker.—The obfermtor of the 
bills of mortality hath given us the bell; account ot the 
number that late plagues have.fwept away. Hale's Orig. of 
Mankind. 
She may be handfome, yet be chafte, you fay. 
Good obfervator, not fo fall away. Dnjden. 
OBSER'VATORY, / [obfervatoire, Fr.] A place built 
for aftronomical obfervations—Another was found near 
the olfervatory in Greenwich Park. Woodu-ard on Fo (fils. 
As navigation elfentially depends on the determinations 
made in obfervatories, fuch eftablifhments have been con- 
fidered of great national importance, efpecially in mari¬ 
time ftates; and hence they have been liberally endowed 
by.different governments. Even private obfervatories 
have been, in many places, eredted at a confiderable ex- 
penfe, and their number has been greatly increafed of 
late years; a circumftance which, while it marks the pro- 
grefs of fcience, does honour to the age in which we live. 
Befides the important advantages of improving nautical 
aftronomy, obfervatories are, in thetnfelves, objects of the 
higheft intereft to every fcientific and liberal mind. Here 
the inventions and difcoveries of the greateft men in all 
ages are united, and applied to the molt grand and ufe- 
ful purpofes. Here theory is reduced to practice, and 
fcience illultrated by art; or, in the words of the poet, 
(applied to an obfervatory,) 
Here truths fublime and facred fcience charm. 
Creative arts new faculties fupply, 
Mechanic powers give more than giant’s arm, 
And piercing optics more than eagle’s eye : 
Eyes that explore creation’s wond’rous laws, 
And teach us to adore the great defigning Caufe. 
In Ihort, an obfervatory maybe confidered as affording the 
molt fublime difplay of the works of God and man. 
All nations where aftronomy has been Itudied or im¬ 
proved, boalt of having had obfervatories at an early pe¬ 
riod, although ancient biltory affords but little informa¬ 
tion on the fubjedt. It was not, indeed, until confider¬ 
able progrefs had been made both in aftronomy and the 
mechanical arts, that any attempts fucceeded either in 
conftrudting inftruments, or eredting edifices for aftrono- 
mical purpofes. 
“ The firft obfervatories of man,” fays the eloquent 
Bailly, “ were the fields, and his eyes his inftruments; 
and liis progrefs with thefe aids alone was aftonifhing.” 
From the fame interefting writer, as well as from other 
good authorities, we learn that the inftruments of ancient 
aftronomers were very large and of rude conftrudtion, 
moftly of wood, and fome of ftone. They confifted chiefly 
of gnomons, dials, and aftrolabes; and long tubes were 
ufed in the way of telefcopes. Deep wells were alfo funk 
in dry places, from the bottom of which theftars might be 
feen in the day-time. Moft buildings for aftronomical 
obfervations were of great altitude, and were chiefly eredted 
in very high fituations. 
In Chaldaea, a country celebrated in the early annals 
of aftronomy, the lofty temple of Belus was ufed as an 
obfervatory; and in Egypt, the famous tomb of Ofyman- 
dias was applied to the fame purpofe. This building is 
faid to have contained a golden circle for celeftial obfer¬ 
vations, which was 365 cubits in circumference, and one 
cubit in thicknefs. Little credit, however, can be given 
to fuch extravagant defcriptions. The pyramids of Egypt 
are, by fome writers, fuppofed to have been originally ob¬ 
fervatories ; and, in lupport of this opinion, it is argued 
that they were built to face the four cardinal points. But 
this practice was very general in ancient times, even in 
the conftrudtion of dvvelling-houfes, which were moftly 
made to front the eaft ; and our Chriftian churches alfo 
have been generally built with a fimiliar attention to the 
points of the compafs. The great height of the pyramids 
was, however, favourable for making celeftial obferva- 
VATOR.y, an 
tions, particularly for the purpofe of aftrology, which was 
a leading ftudy in thofe times, and which chiefly required 
an accurate view of the rifing and fetting of liars. It is, 
however, certain, that pradlical aftronomy was much im¬ 
proved in Egypt, particularly in the famous fchool o£ 
Alexandria, where an obfervatory was built 300 years 
before the Chriftian era, and continued for more than 
five centuries under a fucceffion of celebrated names, 
among which may be mentioned Ariftellus, Hipparchus, 
Ptolemy, &c. 
The Gentoo nations appear to have made a very early 
progrefs both in the theory and practice of aftronomy. 
Thefe people have traditions and veftiges of ancient obfer- 
vatories, upon which ingenious difquifitions may be found 
in Bailly’s Hiftoire de l’Aftronomie Indienne, and in the 
Afiatic Refearcjies, by fir William Jones, Meflrs. Hunter, 
Bentley, Colebrooke, and others. From the obfervatories 
of more modern date in India, an idea may be formed of 
theirantecedent eftablifhments of the kind, as they differ, 
in almoft every particular, from European obfervatories.' 
Thefe Hindoo inftitutions, five in number, w’ere con- 
ftrudted nearly at the fame period, about zoo years agofi 
They were built by order of the emperor Mahomet Shah, 
with a view to reform the calendar by means of aftronomi¬ 
cal obfervations; and he chofefor his principal aftronomer 
Jeyfing, or Jayafinha, the rajah of Ambhere. Thefe ob- 
lervatories were built at Delhi, Benares, Matra, Oujein, 
and Suvai Jeypoor, and all under the direction of Jeyfing. 
The obfervatory at Benares has been defcribcd under 
that word, in vol. ii. an<i, as all the other obfervatories' 
were built and furniftied nearly on the fame plan, we need 
not enlarge, in this place, on the fubjedt of Hindoo obfer¬ 
vatories. 
In China, there was an imperial obfervatory, built at 
Pekin, in the thirteenth century, on the city walls; and in 
1669, father Verbieft, a miffionary Jefuit, having been 
made prefident of the tribunal of mathematics there, and- 
chief obferver, obtained permiflion of the emperor Cam-hi 
to furnifh it with new inftruments, a catalogue of which 
may be feen in Duhalde’s Defcription of China. Other 
obfervatories were built in China fubfequently by the 
French miffionafies, and by the Portuguefe Jefuits, who 
diftinguifhed themfelves very much by their improvements’ 
in aftronomy, notwithifanding the duties of a very diffe¬ 
rent nature in which they were employed, and to which 
they are fuppofed likewife to have paid due attention. 
The inftruments of the Pekin obfervatory are described as 
exceedingly large, but the divifions lefs accurate, and the 
contrivance in fome 'refpedis lefs commodious, than the 
inftruments made at that period in Europe. The chief 
were, a fextant eight-feet radius, a quadrant fix-feet ra¬ 
dius, an.azimuthal horizon, alfo a celeftial globe, and ar¬ 
millary zodiacal fphere, each fix Paris feet diameter. ' 
It is faid that Copernicus, in 1540, was the firlt Euro¬ 
pean who fet an inftrument in the meridian; but it is 
Hated by Weidler, Bailly, and Coftard, that the firlt regu¬ 
lar obfervatory in Europe was eredted at Caffel in 1561,' by 
William I. landgrave of Heffe, who furniftied it with the 
belt inftruments the age could afford. He is faid to have 
made very accurate obfervations, in concert with his friend 
and correfpondent, Tycho Brahe, who was at the above 
period rifing into great fame, and the high expectations 
formed of him were fully anfwered. 
The next obfervatory in Europe that deferves particular 
notice, was that of Tycho Brahe himfelf, which owed its 
origin, according to Bailly, to a very extraordinary caufe. 
This was the appearance of a new liar of the firft mao-ni- 
tude, in the conftellation of Cafliopeia. It was feen^ by 
different aftronomers about the 10th of November) 1572- 
and, as lome of them had been before in the habit of ob- 
fervingthat conftellation, the appearance was fuppofed to 
be inftantaneous, which added to the aftoniftnnent and 
conflernation that univerfally prevailed on the occafion. 
It was brighter than Jupiter or Venus when nearelt to the 
earth, and was vifible to the naked eye at noon-day. 
After 1 
